This article appears in the Spring 2018 issue of The American Prospect magazine. Subscribe here.

With more than 20 candidates and expanded sources of both news and disinformation, the 2016 presidential campaign was a cacophonous circus. And with a result that hinged on razor-thin margins across Michigan, Pennsylvania, and Wisconsin, post-election analyses have been equally disorienting. They have pointed to meddling by the Russian GRU and the American FBI; white people, black people, brown people; Hillary Clinton’s hubris, her charity, her wardrobe; widespread racism, misogyny, piety, fear, and desperation.

With the luxury of hindsight and analytical acumen, political scientists John Sides, Michael Tesler, and Lynn Vavreck have produced an exceptionally well-researched and insightful postmortem that soberly isolates the election’s core significance: a polarizing debate over American identity spurred by immigration and demographic change. The result, Identity Crisis, is a definitive, statistically informed account of the 2016 presidential election.

The trio craft a coherent narrative underpinned by an original analysis of multiple sources of voting records, media content, and public opinion data along with an extensive review of related research and commentary. While its step-by-step recitation of campaign highlights is tedious and sprawling at times, the prose is succinct, and the argument is amply supported with evidence. Through it all, the book finds that the election turned on President Trump’s rhetorical capacity to capture public attention and focus on the transformational impact of immigration on the status of white Americans.

There is a long tradition of books offering the “inside story” of elections, going back to Theodore White’s The Making of the President 1960. The risk with such books is always that the enthralling story yields few lessons that have general application. That is not the case here; three powerful findings emerge:

First, Sides, Tesler, and Vavreck marshal extensive evidence to show that partisanship in the United States has been racialized. The 2016 election helped strengthen ethnic identities among minorities and polarized white people based on their level of formal education. These divisions now predict partisan preferences to an extent unseen before. Indeed, no other factor predicted changes in white partisanship during Obama’s presidency as powerfully and consistently as racial attitudes did. The strength of white identity and anti-immigrant sentiment best predicted support for Donald Trump.

Second, the response to Trump’s employment of divisive cultural issues has inspired “trickle-down tolerance,” not hate. While there is little doubt that his bigoted remarks and policies have emboldened average citizens to act on their own bigotry, the authors find that more Democrats now support marginal and vulnerable communities such as Muslims, undocumented immigrants, and refugees. While this is encouraging, it has hardened the partisan divisions.

And third, as parties became more closely tied to racial identity, the boundaries between them ossified. A good example is what the authors call “racialized economics,” where individualized economic anxiety is replaced by collective economic grievances between competing racial groups. Partisanship has become so strong that it now dominates people’s perceptions about the state of the economy.

A BOOK THIS AMBITIOUS will attract criticism. Some people may say that Identity Crisis lacks rich, personal illustrations, and that is true. Its few vignettes feel obligatory. The authors’ contribution, however, is to make full use of quantitative data to analyze social and political trends and single out the critical drivers of events. Their dispassionate analysis is a refreshing break from a world of vitriol.

Critics may also say that the book’s omniscient narrative belies the fluky character of the 2016 election—and this is also largely true. Sides, Vavreck, and Tesler make frequent references to classic works of American political science and the predictability of certain components of the 2016 cycle. But the book would have been entirely different if, as a result of highly unpredictable events, Hillary Clinton had won the election. The authors do acknowledge surprises but insist those don’t defy the enduring fundamentals of American politics. Their conclusions diverge from much of Vavreck’s earlier work touting economic drivers of voting behavior, and indicate the extent to which she and her co-authors have let the data dictate their conclusions.

Finally, some people will say that the book wields advanced statistical analysis to produce a diagnosis—a devastating diagnosis—but its methods do not produce a remedy. This is largely true, too. The authors’ omniscience appears to end on November 9, 2016. But it would be unreasonable to expect that they could supply a remedy on the basis of their style of analysis. Political “moneyball” is not the same as baseball “moneyball” because voters may change in ways that quantitative techniques cannot always anticipate.

IF THE AUTHORS OF Identity Crisis had ventured further, they might have addressed a number of issues that their book raises. Three questions, in particular, are worth further thought.

First, how can we square ossifying partisanship with a desire for governance by outsiders? In candidates like Arnold Schwarzenegger, Al Franken, Mike Bloomberg, Jesse Ventura, and Ross Perot, American voters have long found business and celebrity profiles attractive, and many such figures have run as independents untethered to the constraining status quo. In 2016, Trump’s association with the Republican Party was perfunctory, and Bernie Sanders’s relationship with the Democratic Party was similarly fraught. With abysmal levels of job approval for Congress and low trust in government institutions, parties have effectively been reduced to necessary evils for candidates. They possess structural power as gatekeepers of electoral success and help organize increasingly unwieldy coalitions. But we cannot rule out a future backlash against outsiders. Emerging research finds that fringe parties in Europe may weaken once they face the pressures of governance and representation. The election of far-right candidates may also placate anti-immigration anxiety and, once cathartically satiated, allow a turn away from identity politics.

Second, is media coverage good even when it is bad? Identity Crisis makes use of extensive data on the nature and frequency of news coverage and connects those trends with public opinion and electoral outcomes. The analysis, however, underscores two conflicting stories. One emphasizes that Donald Trump sucked all the oxygen from his Republican primary competitors with his must-see bravado and unpredictable commentary. Another highlights the persistently negative coverage of both the Trump and Clinton campaigns, including the steady drip of bad news from the FBI’s investigation of Hillary Clinton’s use of a private email server while secretary of state. One wonders if Trump’s manipulation of free media worked because he was running against 16 other primary candidates wrestling for distinction. Perhaps, as a result of ethnic tribalism, impressions of the two nominees had so hardened by the general election that they were unaffected by criticism from the major media. The media created the monster that is Donald Trump but now find it impossible to destroy him.

Finally, what are the prospective risks of a racialized party landscape? This is perhaps the most disconcerting of all the questions raised by Identity Crisis. When partisan differences are matters of priority, common ground may be found. Since the 1990s, however,Democrats and Republicans have cast their differences as arising over values, where compromise is much more difficult. The value differences arise from different ways of life in American society—on the one hand, a cosmopolitan, liberal value orientation largely attributable to ethnic minorities and urban, professional white people; and, on the other hand, a nationalist, provincial, and nostalgic orientation that predominates among whites with less formal education. The prognosis, observable in other countries with racialized partisanship such as Belgium or Trinidad, is that even the most minor disagreements take on an existential importance. The result is not necessarily civil war, but bitter intransigence and paralyzing polarization.

Amid the growing racialization of American politics, Democrats cannot give up all efforts to appeal to white working-class people. It is a large, diverse constituency, and many supported Trump as a symbolic protest vote against Hillary Clinton and 40 years of the status quo. White working-class voters still determine important statewide races and share a number of priorities with non-white working-class people. A Democrat who is unafraid to engage them and their grievances could win many of them back.

Where Democratic leaders find little traction with white working-class people, they may consider pursuing suburban white moderates who are anxious about social instability and appalled by Trump. Both strategies, however, contradict the current push inside the Democratic Party to double down on the country’s demographic prospects and shift the party further to the left at a moment when Republicans are leaving the center unprotected.

For now, the racialization of American politics holds together a Republican Party that was on the verge of disintegration as recently as August 2016. While a deepened tribalism may viscerally satisfy some on the left, Democrats stand to gain little from that development. It weakens the party’s chances outside major cities, and will ultimately weaken the social fabric of our fraying nation. Trump’s plans are clear. Democrats’ response over the next two years will determine whether Americans’ concerns about identity truly do become a national crisis.